Soap-cationic combinations as rinse cycle softeners

ABSTRACT

A fabric softening composition having improved softening and whitening properties comprising a cationic quaternary softener, preferably an imidazolinium softener, and soap in the weight ratio of 1:1 to 2:1 of soap to quaternary.

Froehlich 252/117 United States Patent 1191 1111 3,920,563

Wixon 5] Nov. 18, 1975 [5 SOAP-CATIONIC COMBINATIONS AS 3,578,592 5/1 971 Pontelandolfo; 252/8.8 RINSE CYCLE SOFI'ENERS 3,583,912 6/1971 Clark 252/8.8 3,660,470 5/1972 Hirst..... 252/117 X Inventor: Harold g xon, New 3,681,241 8/1972 Rudy 252/s.s x Brunswick, NJ. 3,703,480 11/1972 Grand et a1 252/8.8 X 3,714,074 1/1973 lnamorato 252/358 X [73] Asslgnee- New 3,716,499 2/ 973 11111111013118... 252/358 x York, 3,730,912 5/1973 1namorato.. 252/358 x [22 il O 31 1972 3,756,950 9/1973 Gluck 252/8.8 X

[ PP N03 302,561 Primary Examiner-Stephen J. Lechert, Jr.

Attorney, Agent, or Firm-Steven J. Baron; Norman [52 US. Cl; 252/s.75; 252/8.8; 252/107; Blumenkcpf; Herbert Sylvester 252/117; 252/121; 117/139.5 F i 51 1111.01. D06M 13/46 [571 ABSTRACT [58] Field of Search 252/8.6, 8.8, 119, 121, A fabric'softening composition having'improved soft- 252/358; 117/ 1395 F ening and whitening properties comprising a cationic quaternary softener, preferably an imidazolinium soft- [56] References Cited ener, and soap in the weight ratio of 1:1 to 2:1 of soap UNITED STATES PATENTS to quatemry- 3,401,119 9/1968 7 Claims, N0 Drawings SOAP-CATIONIC COMBINATIONS AS RINS CYCLE SOFTENERS The present invention relates to a softening composition which imparts to textiles treated therewith a superior degree of softness and whiteness; containing as the essential ingredients a cationic quaternary ammonium compound and soap in amounts varying between a 2:1 and 1:1 ratio of soap to quaternary, depending on the degree of softness and whiteness desired and the particular quaternary and soap blend utilized.

The use of various and diverse chemical materials, and particularly cationic quaternary ammonium compounds as softeners for textile products, is very well known in the art. It is also well known to employ such materials for their softening effect during the laundering operation, and particularly in the rinse cycle of the laundering process. This technique has been necessitated by the fact that the softeners heretofore employed, being mainly cationic in nature, are not compatible with the major type of detergent used in the washing cycle. By far the predominating type of detergent used in home laundering processes is anionic in nature. It has been found that even traces of anionic, materials results in a precipitate which greatly reduces the effectiveness of said cationic fabric softeners. This manifestation of incompatibility has necessitated the use of cationic quaternary softeners during laundering in the rinse cycle after several rinses to free said laundered fabrics of traces of anionic detergent.

Another disadvantage of cationic quaternary softening agents if the well known tendency of textiles treated therewith to yellow.

It has now been found that soaps are compatible with cationic quaternary softening agents and form homogeneous liquid compositions both inside and outside the washer. Furthermore, the softening and whitening performance of the quatemaries are significantly and unexpectedly enhanced by the addition of the soap.

Accordingly, a primary object of this invention is the provision of a cationic quaternary fabric softening composition possessing superior softening properties.

Another object of this invention is to provide a fabric softening composition devoid of any yellowing tendency.

Still another object of this invention is to provide a fabric softening composition possessing superior whiteness properties.

Other objects will appear hereinafter as the description proceeds.

In accordance with the above objects, the fabric softening composition of this invention comprises a cationic quaternary softener and soap in the weight ratio of 1:1 to 1:2 of cationiczsoap.

The cationic quaternary softening agents found use ful in instant invention are commercially known and include quaternary ammonium compounds wherein typically at least one of the groups linked to the nitrogen atom is a higher alkyl group containing at least 12 carbon atoms and two or three of the groups linked to the nitrogen atom are lower alkyl or substituted alkyl groups which contain one to six carbon atoms; one or more of said lower alkyl groups may bear an aryl substituent or may be replaced by an aryl group such as a benzyl group; and there is present an anion such as halogen, acetate, methosulfate, etc. Typical quaternary ammonium compounds are ethyl-dimethyl-stearyl amryl ammonium chloride, dimethyl-methylethyl laurylcetyl ammonium chloride, propyl myristyl ammonium chloride, ditallow-dimethyl ammonium chloride, and

the corresponding methosulfates, acetates, etc.

A preferred group of cationic quaternary ammonium softening agents are the imidazolinium salts, such as: Z-heptadecyll-methyll-[ (2-stearoylamido )ethyl imidazolinium methyl sulfate, Z-heptadecyl- 1 -methyll-[ 2-stearoylamido )ethyl imidazolinium chloride, Z-methyl-1-(2-hydroxyethyl)-l-benzyl imidazolinium chloride,

2-cocol-( 2-hydroxyethyl)- l-benzyl chloride,

2-cocol-(hydroxyethyl)-1-(4-chlorobutyl- )imidazolinium chloride,

2-cocol-( 2-hydroxye thyl 1 -octadecenyl imidazolinium chloride,

2-tall oil fattyl 2-hydro xyethyl l -benzyl imidazolinium chloride,

2-tall oil fatty-l-(2-hydroxyethyl)-l-(4-chlorobutyl) imidazolinium chloride,

2-heptadecenyll 2- hyd'roxyethyl l 4- chlorobutyl)imidazolinium chloride,

Z-heptadecenyll 2-hydroxyethyl l -benzyl imidazolinium chloride,

Z-heptadecyll hydroxye-thyl l -octadecyl imidazolinium ethyl sulfate.

imidazolinium Other known imidazolinium salts possessing softening properties may be utilized herein. 1

The soaps useful in instant invention are commercially known and include water-soluble salts of one or more of the higher fatty acids with an alkali or a metal. Suitable fatty acids include oleic, stearic, palmitic, lauric, erucic, caproic, caprylic, capric, myristic, etc. Fatty oils generally provide a suitable source for the preparation of the water-soluble soaps useful herein, such as tallow, olive oil, coconut oil, mustard seed oil, and the like. The water-soluble soaps include the alkali metal soaps such as sodium and potassium, the ammonium, lower amine and alkanolamine soaps.

Although the incompatibility of even traces of anionics, (soaps are anionic), with cationic quaternary ammonium softeners is well known in the prior art. It has nevertheless been found that soap is compatible with aforesaid quaternary ammonium softeners and unexpectedly enhances the softening and whitening properties thereof. Weight ratios of 1:1 to 2:1 of soaptcationic appear to be most effective, as shown by the following examples utilizing a one Towel Test.

One terry cloth hand towel is washed with threefourths cup (60 gr) commercial detergent in a washer using 17 gallons of tap water at about F. At the beginning of the rinse cycle, 1 capful (30 gr) fabric softener is added. After air drying, the towel is rated for softness on a scale of 1, which represents no softness, to 10, which signifies excellent softness. Ratings'of 10 to l0 are assigned when the towel is particularly soft, more so than obtainable under practical laundry condi tions. Whitening properties are shown on the b scale, wherein higher numerical values of +b means greater benzyl- 3 yellowing, and higher numerical values of b signifies greater whitening.

EXAMPLE 1 A liquid softener was prepared by dispersing 9.5% of a 75% solution of Z-heptadecyl-1-methyl-1-[2- stearoylamido)ethyl] imidazolinium methyl sulfate (7.1% A1) in 89% blue water containing 1.5% ofa 1% solution of Acid Blue No. 80 at about 120F. The resultant composition was opaque, homogenous, and of low viscosity. 30 g of this composition was added at the beginning of the rinse cycle. The towel received a softeness rating of 1O and a b value of 4.8.

EXAMPLE 2 A liquid softener was prepared as in Example 1, except that 4.8% of the quaternary compound (3.6 A1) and 4.0% soap flakes containing 80/20 Tallow, Coco and moisture (3.6Al) was dispersed in the blue water. The resultant composition was opaque, homogeneous, and exhibited a very low viscosity. 30 g of this liquid softener was added to the rinse water and a towel treated therewith as in Example 1. This towel was rated 10 for softness and received a b value of 4.7.

This example represents a 1:1 weight ratio of cationic to soap and exhibited a significant improvement in softness over the towel treated with the cationic alone.

EXAMPLE 3 The softener composition of Example 1 was added to the wash cycle along with the commercial detergent.

EXAMPLE 4 The softener composition of Example 2 was added to the wash cycle together with the commercial detergent. The wet towel of Example 4 was softer than that of Example 3. Thus, it is apparent that the cationic-soap softener is superior to the cationic softener alone, both in the rinse cycle and in the wash cycle of the laundering process.

EXAMPLE 5 The quaternary content of Example 1 was increased to and 1% NaCl was added to reduce the viscosity, thereby yielding a homogeneous, opaque liquid of low viscosity. A towel treated with this softener in the rinse cycle during laundering was given a softness rating of 10 and a b value of 4.5.

EXAMPLE 6 EXAMPLE 7 Only 5 g of the softener composition of Example 1 (7.1% quaternary) is used in the rinse cycle. A towel treated herewith gave a softness rating of 10 and a b value of 3.5.

4 EXAMPLE 8 Only 5 g of the softener composition of Example 2 (7.1% of 1:1 ratio of soap to quaternary) is used in the rinse cycle. A towel treated herewith exhibited a softness of 10 and a brightness value of 3.3.

EXAMPLE 9 Only 5 g of the softener composition of Example 5 (15% quaternary) is used in the rinse cycle, yielding a towel with a softness value of 10 and a b value of 4.2.

EXAMPLE 10 Only 5 g of the softener composition of Example 6 (15% of 1:1 ratio of soap to quaternary) is used in the rinse cycle, yielding a towel with a softness rating of 10 and a b value of -2.0.

The aforedefined examples clearly show that the softness of fabrics treated with the quaternary soap blend is significantly greater than fabrics treated with the quaternary alone, whether using 30 g or 5 g of composition in the rinse cycle. However, optimum softness was obtained with 15% of the 1:1 blend of quaternaryzsoap.

Whiteness when using the 15% quaternaryzsoap blend was better than when using the 15% quaternary alone, with parity at the 7% level.

EXAMPLE 1 l 30 g of a softening composition in accordance with Example 1 containing 14.2% quaternary compound was used to rinse a towel which had not been washed with detergent prior thereto. The treated towel exhibited a softness of 1O and a b value of +2.7.

EXAMPLE 12 30 g of a softening composition in accordance with Example 2 containing 9.5% soap and 4.7% quaternary compound was used in the rinse cycle, in the absence of a previous washing cycle. This represents a 2:1 soap:- quaternary ratio. The rinsed towel was rated 1O on the softness scale and +1.5 on the b scale. The whiteness improvement of the 2:1 ratio is very apparent visually and the softness improvement can be easily felt.

Thus, it is apparent that a greater improvement in whiteness can be achieved by increasing the ratio of soap to quaternary from 1:1 to 2:1. Accordingly, by varying the ratio between 1:1 and 2:1 of soap to quaternary, optimum results as to softness and whiteness are obtainable.

EXAMPLE 13 A liquid softener was preparedin accordance with Example 2 containing 7.1% soap flakes and 7.1% dimethyl ditallow ammonium chloride as a substitute for the imidazolinium compound. 30 g of this softening composition, which was an opaque, low viscosity product, was used to rinse an untreated towel. The rinsed towel was rated 10 on the softness scale and +2.7 on the b scale. Although this quaternary compound is not as effective as the imidazolinium compound, adequate softness and whiteness is obtained therewith. However, the imidazolinium softeners are preferred to obtain both maximum softness and improved whiteness.

The softening composition of instant invention may also include minor amounts of brighteners, bluing, germicides, perfumes, or other additives which do not interfere with the softening and whitening properties of said composition.

X PLE 14 cellulosic fibers, e.g., rayon or other textile fibers, e.g.,

lngredients; 7r (Z-hept'adecyll methyl-l [(Z-stearoylamido )ethyl-l' 915 (7.1 A1 imidazoliniumv methyl sulfate (75% Al) Soap flakes, 80/20 Tallow Coco (90% Al) 8.0 (7.1 Al) *Calcofluor CSL Brightener Solution (23%) 1.2 (0.28 Al) Acid Blue No. 80 (1%) 1.5 Velour Perfume v I 0.3 Water 79.5 4,4 his, 4-anilino-6-ln-(Z-hydroxyethyl)-ri-(2-curbamoylethyl) ariiinols-lriixiim'lfi'lamihog-Zfl' stilbene disulfonic acid.

' The brightener is dispersed in the imidazolinium solution at 120F and the soap flakes are added thereto with stirring. The water is added to said composition,

nylon,silk, wool, polyethylene terephthalate, cellulose acetate, -acrylonitrile polymers or copolymers, or blends of any two or more of these fibers (e.g., cottonto the last rinse cycle during the laundering of fabrics. The same superior results were attained herewith, as in Example 6.

The recommended amount of softening composition useful in the final rinse of wash cycle is 30 to 60 g (l to 2 capfuls), although more or lesser amounts can be utifollowed by the blue color and perfume, yielding an 15 polyester blends). This softening composition may be opaque, low viscosity product. applied to the fabric in an aqueous bath, either as a This product may be prepared and used in liquid 0 final rinse during laundering, or as a separate and dissolid form, adsorbed onto a carrier. The amount of tinct softening operation. In use, to 60 g of the softquatemarytsoap softener present in the liquid composi- 2O ening composition is added to an automatic washing tion may be within the range of 220%, and preferably machine or similar treating bath containing 17 gallons about 715% by weight. The liquid composition may be liters) of water, and an average load of fabrics sprayed on, or otherwise agglomerated with particles of (about 6 to 8 pounds). However, lesser or greater borax, sodium carbonate, sodium bicarbonate, sodium amounts may be utilized to obtain the desired degree of sesquicarbonate, sodium sulfate, sodium chloride, 25 softness and whiteness, depending on the water temphosphate salts, or other carrier materials, to form perature, the amount of water and clothes, etc. granular or powdered compositions. This solid product The presence of traces of anionics from the wash may also be formed into a pellet or other suitable cycle does not adversely affect the superior properties shape. The amount of quaternary:soap softener present of instant rinse product. The following tests prove that in the powdered form may be 230%, and preferably 30 instant softening composition functions equally well 7-20% by weight. after a wash cycle in the presence of traces of anionics due to carryover, or in a separate softening operation EXAMPLE 15 wherein no traces of anionics are present in the rinsing g of a powdered softening composition comprising bath. 7.5% of 2-heptadecyl- 1 methyl- 1 -[2- 35 A cupful (80 g) of commercial detergents was used in stearoylamido)ethyl] imidazolinium methyl sulfate and the wash cycle and subsequently rinsed with a softening 7.5% soap flakes derived from an 80/20 blend of tallow composition. Towels treated herewith were rated for and coconut oil on a sodium sulfate carrier was added softness:

Wash Cycle Final Rinse Softness Detergent Softening Agent Rating b l. Anionic detergent l 2. Same 7.1% Quaternary softener:

Z-heptadecyl-l -methyl- 1 [(2-stearoylamido)ethyl] imidazolinium chloride, (Example l). l0 4.8 3. Same 7.271. 1:1 quaternary softenerzsoap (of Example 2). 1O+++ 4.7 4. Same 15% Quaternary softener.

(Example 5). 10 4.5 5. Same 15% 1:1 quaternary:soap.

(Example 6). 10 5.2 6. No detergent 14.2% quaternary softener. (Example ll). 10 +2.7 7. Same 14.2% 2:1 quaternary:soap.

(Example 12). l0 +1.5

There was a noticeable difference in the degree of whiteness of the towels, rinsed with a 2:1 ratio of soap:-

quaternary.

These results clearly show the unexpectedly superior results obtainable with instant softening formulation,

' which comprises a cationic quaternary softener and a soap within the ratios of 1:1 to 2:1 of soap to quaternary.

While various preferred embodiments of the present invention have been illustrated by means of specific examples, it is to be understood that the present invention is in no way to be deemed as limited thereto, but should 7 be construed as broadly as all or any equivalents thereof.

What is claimed is: l. A fabric-softening composition having improved softening and whitening properties comprising a cati- 8 4. A fabric softening comosition of claim 1, wherein the soap is derived from tallowand/or coconut oil.

5. A method of softening fabrics which comprises applying to said fabrics in an aqueous bath an amount sufficient to soften the fabric, of the composition of claim onic quaternary ammonium softener and soap in the 7 6. The method of claim 5, wherein the softening composition of claim 2 is added during the rinse cycle of laundering.

7. In the process of softening fabrics in water, the improvement which comprises adding to the water the composition of claim 1, in an amount sufficient to soften said fabrics. 

1. A FABRIC-SOFTENING COMPOSITION HAVING IMPROVED SOFTENING AND WHITENING PROPERTIES COMPRISING A CATIONIC QUATERNARY AMMONIUM SOFTENER AND SOAP IN THE WEIGHT RATIO OF 1:1 TO 2:1 OF SOAP TO CATIONIC.
 2. A fabric-softening composition of claim 1, wherein the cationic quaternary ammonium softener is an imidazolinium compound.
 3. A fabric-softening composition of claim 2, wherein the cationic quaternary softener is 2-heptadecyl-1-methyl-1-(2-stearoylamido)ethyl)imidazolinium methyl sulfate.
 4. A fabric softening comosition of claim 1, wherein the soap is derived from tallow and/or coconut oil.
 5. A method of softening fabrics which comprises applying to said fabrics in an aqueous bath an amount sufficient to soften the fabric, of the composition of claim
 1. 6. The method of claim 5, wherein the softening composition of claim 2 is added during the rinse cycle of laundering.
 7. In the process of softening fabrics in water, the improvement which comprises adding to the water the composition of claim 1, in an amount sufficient to soften said fabrics. 